Extracting prog: 5m14.202029564s
Minimizing prog: 43m5.003636969s
Simplifying prog options: 13m34.162422161s
Extracting C: 6m33.302445644s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)
connect$inet(r1, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program did not crash
single: failed to extract reproducer
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)
connect$inet(r1, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program crashed: possible deadlock in smc_release
single: successfully extracted reproducer
found reproducer with 5 syscalls
minimizing guilty program
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
connect$inet(r1, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
listen(r0, 0x9)
connect$inet(0xffffffffffffffff, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)
connect$inet(r1, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): bind$inet-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
bind$inet(0xffffffffffffffff, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(0xffffffffffffffff, 0x9)
connect$inet(r0, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, 0x0, 0x0)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)
connect$inet(r1, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)
connect$inet(r1, 0x0, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
simplifying guilty program options
testing program (duration=6m0s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)
connect$inet(r1, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program did not crash
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
detailed listing:
executing program 0:
r0 = socket$inet_smc(0x2b, 0x1, 0x0)
bind$inet(r0, &(0x7f0000000140)={0x2, 0x4e24, @loopback}, 0x10)
r1 = socket$inet_smc(0x2b, 0x1, 0x0)
listen(r0, 0x9)
connect$inet(r1, &(0x7f0000000000)={0x2, 0x4e24, @loopback}, 0x10)

program crashed: possible deadlock in smc_release
extracting C reproducer
testing compiled C program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$inet_smc-bind$inet-socket$inet_smc-listen-connect$inet
program crashed: no output from test machine
a never seen crash title: no output from test machine, ignore
reproducing took 1h7m9.323674166s
repro crashed as (corrupted=false):
======================================================
WARNING: possible circular locking dependency detected
6.15.0-syzkaller-13659-g5b032cac6225 #0 Not tainted
------------------------------------------------------
syz.0.152/6339 is trying to acquire lock:
ffff88805883b758 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:3924 [inline]
ffff88805883b758 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4178 [inline]
ffff88805883b758 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x4d0/0xcc0 kernel/workqueue.c:4210

but task is already holding lock:
ffff888058839958 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x378/0x5f0 net/smc/af_smc.c:336

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}:
       lock_sock_nested+0x41/0xf0 net/core/sock.c:3752
       smc_listen_out+0x202/0x4a0 net/smc/af_smc.c:1913
       smc_listen_out_connected net/smc/af_smc.c:1933 [inline]
       smc_listen_decline net/smc/af_smc.c:1968 [inline]
       smc_listen_work+0x521/0x50e0 net/smc/af_smc.c:2564
       process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
       process_scheduled_works kernel/workqueue.c:3321 [inline]
       worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
       kthread+0x3c5/0x780 kernel/kthread.c:464
       ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3168 [inline]
       check_prevs_add kernel/locking/lockdep.c:3287 [inline]
       validate_chain kernel/locking/lockdep.c:3911 [inline]
       __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
       lock_acquire kernel/locking/lockdep.c:5871 [inline]
       lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
       touch_work_lockdep_map kernel/workqueue.c:3924 [inline]
       start_flush_work kernel/workqueue.c:4178 [inline]
       __flush_work+0x4e4/0xcc0 kernel/workqueue.c:4210
       __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4366
       smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
       __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
       smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1844
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0xc3c/0x1070 net/smc/smc_close.c:225
       __smc_release+0x634/0x880 net/smc/af_smc.c:277
       smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
       __sock_release+0xb3/0x270 net/socket.c:647
       sock_close+0x1c/0x30 net/socket.c:1391
       __fput+0x402/0xb70 fs/file_table.c:465
       task_work_run+0x150/0x240 kernel/task_work.c:227
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
       exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
       syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
       do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_SMC/1);
                               lock((work_completion)(&new_smc->smc_listen_work));
                               lock(sk_lock-AF_SMC/1);
  lock((work_completion)(&new_smc->smc_listen_work));

 *** DEADLOCK ***

3 locks held by syz.0.152/6339:
 #0: ffff888060874408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #0: ffff888060874408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646
 #1: ffff888058839958 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x378/0x5f0 net/smc/af_smc.c:336
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4152 [inline]
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xfb/0xcc0 kernel/workqueue.c:4210

stack backtrace:
CPU: 0 UID: 0 PID: 6339 Comm: syz.0.152 Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2046
 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3168 [inline]
 check_prevs_add kernel/locking/lockdep.c:3287 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
 lock_acquire kernel/locking/lockdep.c:5871 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
 touch_work_lockdep_map kernel/workqueue.c:3924 [inline]
 start_flush_work kernel/workqueue.c:4178 [inline]
 __flush_work+0x4e4/0xcc0 kernel/workqueue.c:4210
 __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4366
 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
 __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1844
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0xc3c/0x1070 net/smc/smc_close.c:225
 __smc_release+0x634/0x880 net/smc/af_smc.c:277
 smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
 __sock_release+0xb3/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1391
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4d7098e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff5a71b718 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000057a39 RCX: 00007f4d7098e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f4d70bb7ba0 R08: 0000000000000001 R09: 000000055a71ba0f
R10: 00007f4d70800000 R11: 0000000000000246 R12: 00007f4d70bb5fac
R13: 00007f4d70bb5fa0 R14: ffffffffffffffff R15: 00007fff5a71b830
 </TASK>

final repro crashed as (corrupted=false):
======================================================
WARNING: possible circular locking dependency detected
6.15.0-syzkaller-13659-g5b032cac6225 #0 Not tainted
------------------------------------------------------
syz.0.152/6339 is trying to acquire lock:
ffff88805883b758 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: touch_work_lockdep_map kernel/workqueue.c:3924 [inline]
ffff88805883b758 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: start_flush_work kernel/workqueue.c:4178 [inline]
ffff88805883b758 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}, at: __flush_work+0x4d0/0xcc0 kernel/workqueue.c:4210

but task is already holding lock:
ffff888058839958 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x378/0x5f0 net/smc/af_smc.c:336

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_SMC/1){+.+.}-{0:0}:
       lock_sock_nested+0x41/0xf0 net/core/sock.c:3752
       smc_listen_out+0x202/0x4a0 net/smc/af_smc.c:1913
       smc_listen_out_connected net/smc/af_smc.c:1933 [inline]
       smc_listen_decline net/smc/af_smc.c:1968 [inline]
       smc_listen_work+0x521/0x50e0 net/smc/af_smc.c:2564
       process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
       process_scheduled_works kernel/workqueue.c:3321 [inline]
       worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
       kthread+0x3c5/0x780 kernel/kthread.c:464
       ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 ((work_completion)(&new_smc->smc_listen_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3168 [inline]
       check_prevs_add kernel/locking/lockdep.c:3287 [inline]
       validate_chain kernel/locking/lockdep.c:3911 [inline]
       __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
       lock_acquire kernel/locking/lockdep.c:5871 [inline]
       lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
       touch_work_lockdep_map kernel/workqueue.c:3924 [inline]
       start_flush_work kernel/workqueue.c:4178 [inline]
       __flush_work+0x4e4/0xcc0 kernel/workqueue.c:4210
       __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4366
       smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
       __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
       smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1844
       smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
       smc_close_active+0xc3c/0x1070 net/smc/smc_close.c:225
       __smc_release+0x634/0x880 net/smc/af_smc.c:277
       smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
       __sock_release+0xb3/0x270 net/socket.c:647
       sock_close+0x1c/0x30 net/socket.c:1391
       __fput+0x402/0xb70 fs/file_table.c:465
       task_work_run+0x150/0x240 kernel/task_work.c:227
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
       exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
       syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
       do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_SMC/1);
                               lock((work_completion)(&new_smc->smc_listen_work));
                               lock(sk_lock-AF_SMC/1);
  lock((work_completion)(&new_smc->smc_listen_work));

 *** DEADLOCK ***

3 locks held by syz.0.152/6339:
 #0: ffff888060874408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #0: ffff888060874408 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646
 #1: ffff888058839958 (sk_lock-AF_SMC/1){+.+.}-{0:0}, at: smc_release+0x378/0x5f0 net/smc/af_smc.c:336
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: start_flush_work kernel/workqueue.c:4152 [inline]
 #2: ffffffff8e5c4cc0 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xfb/0xcc0 kernel/workqueue.c:4210

stack backtrace:
CPU: 0 UID: 0 PID: 6339 Comm: syz.0.152 Not tainted 6.15.0-syzkaller-13659-g5b032cac6225 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2046
 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3168 [inline]
 check_prevs_add kernel/locking/lockdep.c:3287 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
 lock_acquire kernel/locking/lockdep.c:5871 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
 touch_work_lockdep_map kernel/workqueue.c:3924 [inline]
 start_flush_work kernel/workqueue.c:4178 [inline]
 __flush_work+0x4e4/0xcc0 kernel/workqueue.c:4210
 __cancel_work_sync+0x10c/0x130 kernel/workqueue.c:4366
 smc_clcsock_release+0x5f/0xe0 net/smc/smc_close.c:29
 __smc_release+0x5c2/0x880 net/smc/af_smc.c:301
 smc_close_non_accepted+0xda/0x200 net/smc/af_smc.c:1844
 smc_close_cleanup_listen net/smc/smc_close.c:45 [inline]
 smc_close_active+0xc3c/0x1070 net/smc/smc_close.c:225
 __smc_release+0x634/0x880 net/smc/af_smc.c:277
 smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344
 __sock_release+0xb3/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1391
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x150/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4d7098e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff5a71b718 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000057a39 RCX: 00007f4d7098e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f4d70bb7ba0 R08: 0000000000000001 R09: 000000055a71ba0f
R10: 00007f4d70800000 R11: 0000000000000246 R12: 00007f4d70bb5fac
R13: 00007f4d70bb5fa0 R14: ffffffffffffffff R15: 00007fff5a71b830
 </TASK>